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Recent years has witnessed China’s vigorous promotion of the excellent traditional Chinese culture. And major TV channels have launched numerous outstanding programs and works, among which the series of “Chinese Festivals” released by Henan Satellite TV has achieved “success across fields”. Not only does it provide a good example for the re-creation and dissemination of traditional culture, but it also presents a new trend of inheriting, innovating and developing excellent traditional Chinese culture.

The nighttime economy, or NTE—the combination of nocturnal specialties and the extension of the diurnal economy into the night—has been implemented as an effective boosting instrument set to “revitalize the urban space”. The instrument, applied in regions around world, develops new socioeconomic dynamics and poles of growth within cities. Although some cases emphasize the functional success of NTE practices, disequilibrium between urban elements—social groups, communities, and the cultures in which they live—are ongoing. The present article argues that urban nights must be considered within a broader reflection on the question of sustainability because a closer integration between brands, cultural elements, employment, and capital in different scales is demonstrated at night. Based on growth pole theory, this study combines data mining, spatial modeling, and other complementary approaches, and successfully (1) identifies the growth poles of the NTE in Lanzhou City, a postindustrial city transitioning towards a nighttime economy that forms dotted and non-uniform nocturnal zones through its geography and demography; (2) characterizes their socioeconomic organization, and (3) analyzes various causes and manifestations of the disequilibrium.

Diffraction–radiation of regular waves by a body such as an offshore structure or a moored ship is considered within the classical framework of potential-flow theory, which is commonly used because it is realistic and practical. A simple analysis that is based solely on straightforward applications of Green’s classical identity to a ‘free-waterplane’ flow-model and a ‘rigid-waterplane’ flow-model is expounded. These alternative flow-models and the related straightforward applications of Green’s identity yield an elementary yet rigorous justification of the practical and effective method, called ‘combined boundary integral equation method’ (CBIEM), of Lau and Hearn for preventing irregular frequencies. This method is shown to be significantly more efficient, and arguably simpler and more logical, than the widely-used extended boundary integral method of Lee and Newman. A modification of the ‘combined boundary integral equation method’ is also given. This modification involves a pair of boundary integral equations that are mathematically equivalent to the pair of integral equations solved in the CBIEM, but are weakly singular.

The behavior of an offshore structure in regular waves – and the related (linear and nonlinear) wave loads, added-mass and wave-damping coefficients, and body-motions – are commonly analyzed via the Green-function and boundary-integral method associated with potential-flow theory. This realistic, widely-used method requires accurate and efficient numerical evaluation of flows created by distributions of singularities (source, dipole) over (flat or curved) panels of various shapes (triangle, quadrilateral) that are used to approximate the surface of an offshore structure. This basic core element of the theory of diffraction–radiation of regular waves by an offshore structure is considered for water of uniform finite depth. The special case of deep water is also considered. An analytical representation of the flow created by a general distribution of singularities over a hull-surface panel is given. This flow-representation is based on the Fourier–Kochin (FK) approach, in which space-integration over the panel is performed first and Fourier-integration is performed subsequently, unlike the common approach in which the Green function (defined via a Fourier integration) is evaluated first and subsequently integrated over the panel. The analytical and numerical complexities associated with the numerical evaluation and subsequent panel integration of the singular Green function for wave diffraction–radiation by offshore structures are then avoided in the FK approach. In this approach, panel integration merely amounts to integrating an elementary (exponential–trigonometric) function, a trivial task that can be performed accurately and efficiently. The analytical flow-representation given in the study provides a mathematically-exact smooth decomposition of free-surface effects into a non-oscillatory local flow and waves. The waves in this flow decomposition are defined by a regular single Fourier integral, and the local flow is given by a double Fourier integral with a smooth integrand that only involves ordinary functions and is dominant within a compact region near the origin of the Fourier plane. Illustrative numerical applications for typical distributions of sources and dipoles over a panel show that the flow-representation given in the study is well suited for practical numerical evaluations.

The 3D frequency-domain analysis of the flow around a ship advancing in regular waves, in deep water, via the Green-function and boundary-integral method requires a practical and reliable way of evaluating the flow due to an arbitrary distribution of singularities (sources and dipoles) over the (flat or curved, quadrilateral or triangular) panels that are commonly used to approximate a ship hull-surface. This crucial element of the Green-function method, also widely called panel method, in a 3D analysis of ship motions is classically performed via a two-step procedure that involves evaluation of the Green function G and its gradient ∇ G as a first step, and their subsequent integration over hull-surface panels. This usual direct method, widely studied and applied in the literature, involves notorious well-documented mathematical and numerical complexities. A novel alternative method, based on the Fourier–Kochin approach, is expounded in the study. In this method, evaluation of G and ∇ G is bypassed, i.e. G and ∇ G are not evaluated, and the flow due to a distribution of singularities is evaluated directly, in the manner already expounded for the particular cases of steady flow around a ship advancing in calm water and diffraction-radiation of regular waves by an offshore structure or a ship at zero forward speed. The method expounded in these previous studies and extended here is based on an analytical representation of the flow due to a distribution of singularities (including the special case of a Green function and its gradient) that yields a formal decomposition into a wave component, given by single Fourier integrals along the dispersion curves associated with the dispersion relation, and a non-oscillatory local-flow component given by a double integral that has a smooth integrand mostly dominant within a compact region of the Fourier plane. An important aspect of this analytical flow decomposition is that the wave and local-flow components are smooth, unlike the wave and local-flow components in the expressions for G and ∇ G given in the literature. Moreover, the analytical representation of the flow due to a distribution of singularities given in the study provides a practical mathematical basis that is well suited for accurate and efficient numerical evaluation, as is demonstrated via the illustrative applications reported previously for steady flow around a ship advancing in calm deep water and diffraction-radiation of regular waves by an offshore structure in deep water, and reported here for the more general case of a ship advancing in deep water at a constant speed V through regular waves of frequency ω in the regime τ ≡ V ω ∕ g 1 ∕ 4 where g denotes the acceleration of gravity.

Diffraction-radiation of regular waves by offshore structures and flows around ships advancing in calm water or in regular waves are commonly analyzed via potential-flow methods based on the Green functions that satisfy the corresponding free-surface boundary conditions. This realistic, practical, and widely-used approach requires evaluation of free-surface flows due to arbitrary (notably constant, linear or quadratic) distributions of singularities (sources and dipoles) over (flat or curved) panels of various shapes (notably rectangles and triangles). Indeed, reliable, efficient and practical methods to evaluate the flows due to arbitrary singularity-distributions over hull-surface panels is a crucial core-element of the Green-function method in ship and offshore hydrodynamics. This core-issue is the object of the study. Free-surface flows due to singularity-distributions over panels (and related ‘influence coefficients’) are ordinarily evaluated via a two-step procedure that involves evaluation of a Green function G and its gradient ∇ G (a Fourier integration) and subsequent integration of G and ∇ G over a panel (a space integration). This common approach involves notorious analytical and numerical complexities related to the complicated singularities of the Green functions in ship and offshore hydrodynamics. An alternative general approach, applicable to generic dispersion relations and arbitrary distributions of singularities, is expounded. This alternative approach is based on a Fourier–Kochin representation of free-surface effects, in which the space integration over hull-panels is performed first and the Fourier integration is performed subsequently. Thus, the Green function and its gradient are not evaluated in this approach. Indeed, this usual first step is bypassed, and the flow due to a singularity distribution is evaluated directly. A major advantage of the Fourier–Kochin method is that the panel-integration is a trivial task as it merely involves integration of an exponential–trigonometric function. A crucial element of the approach expounded in the study is a general analytical decomposition of free-surface effects into waves and a local flow. The waves in this fundamental flow decomposition are expressed as single integrals along the dispersion curves defined by the dispersion relation in the Fourier plane, and the local flow is given by a double Fourier integral that has a smooth integrand dominant within a compact region of the Fourier plane. This analytical flow representation does not involve approximations, i.e. is mathematically exact, as is verified via numerical applications for two main classes of flows in ship and offshore hydrodynamics: ships advancing in calm water, and diffraction-radiation of regular waves by offshore structures. These applications also demonstrate that the general approach expounded in the study provides a practical, remarkably simple, basis that is well suited for accurate and efficient evaluation of flows due to arbitrary singularity-distributions. Indeed, the approach yields a smooth wave and local-flow decomposition that avoids the complexities related to the evaluation and subsequent hull-panel integration of the singular wave and local-flow components in the classical Green functions of ship and offshore hydrodynamics. The general approach expounded in the study is applicable to other classes of flows, notably wave diffraction-radiation by ships advancing through waves in deep water and by offshore structures in finite water-depth, and these important particular applications will be considered in sequels to the study.

A recently-proposed analytical approximation to farfield ship waves – called Kelvin–Havelock–Peters (KHP) approximation because it combines three classical asymptotic approximations given by Kelvin, Havelock and Peters – is further considered. Specifically, a more accurate KHP approximation is given for a classical generic wave integral, and is applied to steady ship waves and transient capillary-gravity waves. Both the KHP approximation given previously and the refined KHP approximation obtained here only involve elementary functions and are then fully analytical, whereas the Chester, Friedman, Ursell (CFU) asymptotic approximation involves the Airy function and its derivative. Moreover, the KHP approximations – like Kelvin’s classical approximation but unlike the CFU approximation – provide an explicit decomposition of the two systems of waves (called transverse and divergent waves in the special case of ship waves) that exist inside the cusps of the wave pattern. This formal decomposition, and the simplicity of the KHP approximations, are two notable useful features that render the fully analytical KHP approximations well suited, and arguably preferable to the CFU approximation, for practical applications.

The Fourier–Kochin representation of the oscillatory part of the flow pressure at the hull surface of a ship that travels at a constant speed in calm water of large depth – and the related Fourier–Kochin representations of the wave drag, hydrodynamic lift and pitch-moment experienced by the ship – are considered within the framework of the potential flow theory based on the Green function that satisfies the Kelvin–Michell linear boundary condition at the free surface. The convergence of the Fourier integrals in these Fourier–Kochin representations of the flow pressure, the wave drag, the lift and the pitch-moment are studied via a parametric numerical analysis, based on Hogner’s approximate theory, for two families of 120 simple ship models at Froude numbers F within the range 0 . 15 ≤ F ≤ 2 . The analysis shows that the cutoff wavelength λ ∞ associated with negligible short waves is significantly influenced by the Froude number and the hull shape, and yields an analytical relation that explicitly determines λ ∞ in terms of F and three major hull-shape parameters: beam/length ratio, draft/length ratio, and (nondimensional) bow or midship lengths.

The Kelvin–Havelock–Peters farfield approximation is applied to illustrate the influence of the Froude number F based on a ship length L , and – for a body below the free surface – the influence of the Froude number F Δ based on the submergence depth Δ , on a ship wave pattern in deep water. The influence of the Froude number F is illustrated for a free-surface piercing monohull ship; and the influence of the Froude number F Δ is illustrated for a point source submerged at a depth Δ below the free surface. The influences of F and of the submergence depth Δ ∕ L , which is related to F Δ and is used instead of F Δ , are illustrated for a fully-submerged body. These numerical illustrations show that a ship wave pattern – which does not depend on L and Δ within Kelvin’s classical analysis for a ship modeled as a 1-point wavemaker – in fact is greatly influenced by the Froude numbers F and F Δ . In particular, at high Froude numbers, e.g. at F = 1 . 5 , a ship wave pattern mostly contains divergent waves that are most apparent well inside the cusps of the Kelvin wake due to interferences between the dominant waves created by the bow and the stern of the ship, as was previously explained. A very different wave pattern is obtained at low Froude numbers, e.g. at F = 0 . 2 , for which the dominant waves are found outside the cusps of the Kelvin wake. Indeed, the wave patterns created by surface-piercing or submerged bodies can differ greatly from Kelvin’s classical pattern of transverse and divergent waves found inside a 39° wedge aft of a ship.

Alternative boundary-integral representations of linear potential flow around a ship that travels at a constant speed in regular (time-harmonic) waves in deep water are considered. In particular, the Neumann–Michell (NM) boundary-integral representation of steady flow around a ship traveling in calm water is extended to ship motions in regular waves. This extension is straightforward, but points to a complicated and unresolved fundamental issue that is essentially related to the formulation of a linear flow model. Indeed, the NM boundary-integral flow representation for ship motions in regular waves given in the study suggests that the classical Neumann–Kelvin (NK) flow model may be inadequate at a ship waterline. Alternative NM boundary-integral representations of time-harmonic ship waves that are consistent with the previously given NM representation of ship waves in calm water, and yield Fourier–Kochin representations of ship waves that are well suited for numerical computations, are given.

The Green function for diffraction radiation of regular waves in deep water is considered. The Green function G and its gradient ∇G involve non-oscillatory local-flow components L and ∇L, for which simple global approximations valid within the entire flow region exist, and wave components W and ∇W. The waves W and ∇W in this basic decomposition involve the intrinsic Fortran Bessel functions J0(h) and J1(h), where h denotes the horizontal distance between the source and flow-field points in the Green function, and the Struve functions H ˜ 0 ( h ) and H ˜ 1 ( h ) for which complementary approximations valid within the nearfield or farfield ranges 0 ≤ h ≤ 3 or 3 H ˜ 0 ( h ) and H ˜ 1 ( h ) defeat the global nature of the approximations to the local-flow components L and ∇L. This issue, however, is readily remedied if practical approximations, given by Aarts and Janssen in 2016, that relate the Struve functions H ˜ 0 ( h ) and H ˜ 1 ( h ) to the Bessel functions J0(h) and J1(h) are used. The resulting approximations to the waves W and ∇W given here, and the global approximations to the local-flow components L and ∇L given previously, yield practical and particularly simple approximations to G and ∇G that are valid within the entire flow region, can be evaluated simply and efficiently, and are sufficiently accurate for practical applications.

Short-wave approximations are obtained within the framework of the Neumann–Michell (NM) linear theory of potential flow around a ship that travels at a constant speed in calm water. Specifically, the integral over the ship hull surface – that determines ship waves within the Fourier–Kochin representation related to the NM theory – is approximated as a line integral around the ship waterline via Laplace’s method. This waterline-integral approximation is further approximated via Kelvin’s method of stationary phase. The short-wave asymptotic approximations obtained via successive applications of Laplace’s method and Kelvin’s method of stationary phase provide theoretical insight into short (transverse and divergent) waves created by ships that travel at low Froude numbers, and short divergent waves created by ships traveling at moderate or high Froude numbers. In particular, these analytical approximations show that short ship waves are related to the Froude number and the hull form in a fairly complicated manner.

The classical asymptotic approximations to farfield ship waves given by Kelvin, Peters and Havelock for points located inside, outside or at the cusps of the Kelvin wake, and the uniform approximation given by Ursell, are considered. A simple approximation that is nearly equivalent to the Kelvin and Peters approximations inside or outside the cusps of the Kelvin wake, but is finite and agrees with Havelock’s approximation at the cusps, is given. This approximation only involves elementary functions, whereas Ursell’s approximation involves the Airy function and its derivative. The simple approximation given here, based on a modification of Ursell’s uniform approximation, combines the approximations given by Kelvin, Havelock and Peters and is then called the Kelvin–Havelock–Peters (KHP) approximation. This approximation is less accurate than Ursell’s approximation. However, the KHP approximation is more realistic than, yet as simple as, Kelvin’s and Peters’ approximations, which are singular at the cusps.

Basic models of the farfield waves created by a monohull ship or a catamaran that travels at a constant speed in calm water of uniform finite depth are considered. A classical basic model is the 1-point ship model introduced by Kelvin in 1887 for deep water and extended to uniform finite water depth by Havelock in 1908. Another basic model is the 2-point ship model, which considers the two dominant waves created by the bow and the stern of a monohull ship or by the twin bows of a catamaran, and therefore accounts for main wave interference effects. These 2-point ship models contain information that cannot be found in the classical patterns for the 1-point ship model commonly used since Kelvin. In particular, whereas Havelock’s classical wave patterns for the 1-point model only depend on the Froude number based on the water depth, the farfield waves for the 2-point models of a monohull ship or a catamaran also depend on the Froude number associated with the length of the monohull ship or the spacing between the twin hulls of the catamaran. Moreover, the ‘apparent wake angles’ associated with the highest waves that result from constructive wave interferences can greatly differ from the cusp or asymptote angles of Havelock’s wave patterns. Keywords: Farfield ship waves, Shallow water, Ship models, Wave interferences

Computations of linear wave loads and second-order mean drift forces for a hemisphere and a freely floating FPSO show that global analytical approximations, given by Wu et al. in 2017, to the local flow components in the Green function and its gradient yield numerical predictions that closely agree with numerical results obtained via a highly-accurate Green function, as well as analytical results for a hemisphere. The computations reported here provide strong evidence that the global analytical approximations, valid within the entire flow region, are sufficiently accurate to compute linear and mean drift wave loads in practice.

The remarkably simple yet realistic Hogner model of farfield ship waves, previously considered to analyze the apparent wake angle associated with the highest waves that result from constructive interferences among the divergent waves created by a fast ship in deep water, is applied to the more general case of uniform finite water depth. This theory is used to illustrate notable features of ship waves in finite water depth. In particular, numerical applications to a monohull ship and catamarans illustrate two notable features of ship waves in shallow water: specifically, the apparent wake angle can be much smaller than Havelock's classical asymptote or cusp angles, and the apparent wake angle in finite water depth is nearly identical to the apparent wake angle in deep water if the water depth is greater than the ship length. Moreover, the numerical illustrations demonstrate the paramount importance of interferences among divergent waves for fast ships. Indeed, constructive interferences among the divergent waves created by a fast ship largely determine the variation of the amplitude of the waves across the ship wake, and therefore the apparent wake angle and the wave drag of the ship, a critical element of ship design. These numerical illustrations also corroborate main conclusions of an approximate analysis of wave interferences in shallow water for monohull ships and catamarans modeled as 2-point wavemakers.

Kelvin’s classical 1-point ship model, the basic 2-point models of a monohull ship and a catamaran previously studied via elementary geometrical considerations, optimal versions of these two basic 2-point models, and a 4-point model of a catamaran (not considered previously) are analyzed within a common theoretical approach based on potential flow theory, the Green function associated with the Kelvin–Michell linear boundary condition at the free surface, the related Fourier representation of farfield ship waves, and the farfield stationary-phase approximation. The analysis shows that the apparent wake angle associated with the highest waves found inside the cusps of the Kelvin wake as a result of interferences among the divergent waves created by a ship at a high Froude number can be realistically predicted via elementary ship models. In particular, the apparent wake angles for monohull ships and catamarans can be predicted very well via a 2-point model or a 4-point model. Moreover, these models provide basic insight into main features of the farfield waves created by fast ships. Notably, differences between the amplitudes of the bow and stern waves are shown to have no influence on the occurrence of constructive or destructive interferences, although they affect the intensity of wave-interference effects (strong if the amplitudes of the bow and stern waves are commensurate, weak otherwise). Another notable conclusion is that lateral interference effects become more important as the Froude number increases. Indeed, lateral interferences between the twin hulls of a catamaran dominate longitudinal interferences between the fore and aft of the ship at Froude numbers greater than about 1. However, longitudinal interferences between the bow and the stern waves remain dominant for common fast monohull ships.

The far-field waves, and the related far-field wave drag, predicted by the Michell or Hogner theories are considered. These two classical theories are found to predict nearly identical transverse waves for all practical cases. However, the Michell and Hogner models predict divergent waves—dominant at high Froude numbers—that can differ significantly. Differences between the far-field waves predicted by the Michell and Hogner models are much smaller for catamarans, for which lateral interferences between the twin hulls overwhelm lateral interferences between the port and starboard sides of the hulls, than for monohull ships. Moreover, differences between the divergent waves predicted by the Michell and Hogner theories are larger for higher Froude numbers, bigger beam/length ratios, smaller draft/length ratios, or larger separation distances between the twin hulls of a catamaran.

The Green function of the theory of diffraction radiation of time-harmonic (regular) waves by an offshore structure, or a ship at low speed, in deep water is considered. The Green function G and its gradient ∇ G are expressed in the usual manner as the sum of three components that correspond to the fundamental free-space singularity, a non-oscillatory local flow, and waves. Simple approximations that only involve elementary continuous functions (algebraic, exponential, logarithmic) of real arguments are given for the local flow components in G and ∇ G . These approximations are global approximations valid within the entire flow region, rather than within complementary contiguous regions as can be found in the literature. The analysis of the errors associated with the approximations to the local flow components given in the study shows that the approximations are sufficiently accurate for practical purposes. These global approximations provide a particularly simple and highly efficient way of numerically evaluating the Green function and its gradient for diffraction radiation of time-harmonic waves in deep water.

Constructive interference among the divergent waves created by sources and sinks distributed over the hull surface of a ship that advances at high speed in calm water results in highest waves along ray angles located inside the cusps of the classical Kelvin wake. These highest waves are much shorter than the waves along the cusps of the Kelvin wake and are also significantly shorter than the ship length. The ray angles of the highest ship waves and their wavelengths are only weakly influenced by the hull shape, and indeed are kinematic flow features that are known for all monohull ships and catamarans; moreover, these angles and wavelengths are determined via simple analytical relations in terms of the Froude number and, for a catamaran, the distance between the twin bows of the catamaran. These simple general results about the highest waves created by a fast ship widely expand the classical results obtained by Kelvin in 1887 for a ship modeled as a one-point wavemaker.

By a newly developed algorithm to compute global nonadiabatic switching probability only using electronic adiabatic potential energy surfaces and its gradients, we could able to perform on-the-fly trajectory surface hopping molecular dynamics at the SA-CASSCF(14, 8)/6-31G* quantum level to investigate the photo-induced 1,3-cyclohexadiene ring opening reaction from 1,3-cyclohexadiene (CHD) to 1,3,5-hexatriene (HT). We found four conical intersection zones within three singlet low-lying electronic states, in which 1B/2A and 1A/2A are well known to be the most important conical intersection zones to govern dynamics of ring opening reaction. The present simulation gained insight into nonadiabatic dynamics in which 516 sampling trajectories out of 600 can switch back and forth between two involved potential energy surfaces not only at 1B/2A, but also at 1A/2A. This insight is the key to influence quantum yields and time scales of the ring opening reaction. We estimated time constants as 46 fs, 82 fs, and 120 fs, respectively for crossing 1B/2A and 1A/2A, and excited-state lifetime in comparison with corresponding experimental values 56 fs, 80 fs and 130 fs. We estimated quantum yield 0.47/0.53 to HT/CHD in comparison to experiment values 0.30/0.70 in the gas-phase and 0.41/0.59 in the condense-phase. Moreover, the present simulation within 600 sampling trajectories indicates that there is no five membered ring forming in agreement with experiment results and with prediction from the previous wave-packet simulation as a rare case.

To provide insight into optimizing flue gas treatment, simultaneous removal of elemental mercury (Hg0) and NO using a CeO2 modified V2O5–WO3/TiO2 catalyst was investigated. The results show that a novel V2O5–WO3/TiO2–CeO2 catalyst exhibits excellent Hg0 oxidation efficiency (88%) and NO conversion efficiency (89%) at 250 °C. Furthermore, CeO2 modified V2O5–WO3/TiO2 not only exhibits enhanced catalytic activity but also good resistance in SO2 and H2O. These catalysts were also characterized using BET, SEM, XRD, XPS, and H2-TPR. We found lower crystallinity, more reduced species and better texture properties to be presented, which were all ascribed to CeO2 doping. Also, the redox cycle (V4+ + Ce4+ ↔ V5+ + Ce3+) plays a key role in promoting Hg0 oxidation and NO conversion. In tune with the experimental results, a mechanism for the simultaneous removal of Hg0 and NO was proposed for the V2O5–WO3/TiO2–CeO2 catalysts.

The present work investigated the enzymolysis kinetics, thermodynamics and model of porcine cerebral protein (PCP) which was pretreated by single-frequency countercurrent and pulsed ultrasound. The kinetic constants for ultrasonic pretreated and traditional enzymolysis have been determined. Results showed that the value of KM in ultrasonic PCP (UPCP) enzymolysis decreased by 9% over that in the traditional enzymolysis. The values of reaction rate constant (k) for UPCP enzymolysis increased by 207%, 121%, 62%, and 45% at 293, 303, 313 and 323 K, respectively. For the thermodynamic parameters, ultrasound decreased activation energy (Ea), change in enthalpy (ΔH) and entropy (ΔS) by 76%, 82% and 31% in PCP, respectively. However, ultrasound had little change in Gibbs free energy (ΔG) value in the temperature range of 293-323 K. Therefore, a general kinetic equation for the enzymolysis model of UPCP by a simple empirical equation was suggested. The experimental values fits with the enzymolysis kinetic model with a low average relative error (4%) confirmed that the kinetic model was accurate to reflect the enzymolysis process. The positive effect of single-frequency countercurrent and pulsed ultrasound in this study and application of the kinetic model may be useful for the release of bioactive peptides from meat processing by-products.

A polysaccharide termed Se-GP11 was extracted and purified from Se-enriched Grifola frondosa in our previous study. This study investigated the characterization, anti-tumor and immunomodulatory activity of Se-GP11. The results showed that Se-GP11 was composed of mannose, glucose and galactose with a molar ratio of 1:4.91:2.41. The weight-average molecular weight (Mw) and weight-average mean square radius (Rw) of Se-GP11 in 0.1M sodium chloride solution were 3.3×10(4)Da and 32.8 nm. Se-GP11 existed as a globular conformation with random coil structure. Se-GP11 had no anti-tumor activity against HepG-2 cells in vitro, and it significantly inhibited the growth of Heps tumor in vivo. Se-GP11 increased the relatively thymus and spleen weights as well as serum necrosis factor-alpha (TNF-α) and interleukin-2 (IL-2) levels. In addition, Se-GP11 promoted the phagocytosis and NO production of RAW264.7 as compared with that of the normal control group. The results revealed that the Se-GP11 may exhibit the anti-tumor through improving immunologic function of the tumor bearing mice.

Errors that stem from a practical analytical approximation L a to the local flow component L in the Green function associated with steady linear potential flow around a ship hull are considered. Although the approximation L a is not very accurate, the flow potentials evaluated via the exact local flow component L or the approximation L a for Froude numbers F = 0.15 , 0.3 and 0.5 cannot be distinguished, except at F = 0.15 for which relatively small differences can be observed. Moreover, the sinkage, the trim angle and the wave drag predicted by the Neumann–Michell (NM) theory, with the local flow potential evaluated using L or L a , are in very close agreement. Despite its remarkably simplicity, the analytical approximation L a can then be used to compute the local flow component L in the Green function, in the entire flow region, within the framework of the NM linear potential flow theory and the related Hogner approximation. The practical analytical approximation L a is far more practical than the basic integral representation of L , and is an important element of the NM theory. Indeed, the analytical approximation L a , and other features of the NM theory, make it possible to compute the flow around a steadily advancing ship hull in a highly efficient way, as required for routine practical applications to design and hull-form optimization.

Grifola frondosa has long been known and respected as a medically important fungus. This study investigated the characterization, antitumor and immunomodulatory activity of a polysaccharide named GP11 purified from G. frondosa. The results revealed that GP11 was composed of → 1)-D-Manp-(6 →,→ 1)-D-Glcp-(4 →,→ 1)-D-Galp-(6 → and → 2,3,6)-D-Glcp-(1 →, with branches attached at O-2,3 of 1,2,3,6-linked Glcp residues and terminal T-Glcp. GP11 exhibited indirect cytotoxic activity against HepG-2 cells in vitro, and it significantly inhibited the growth of Heps cells in vivo. GP11 increased the relative thymus and spleen weights as well as serum tumor necrosis factor-alpha and interleukin-2 levels. GP11 stimulated tumoricidal activity and the production of nitric oxide (NO), TNF-α and interleukin-1β, and it also stimulated the protein expression of iNOS and mRNA expression of iNOS and TNF-α. TLR-4 is a potential receptor for GP11-mediated macrophage activation. The results suggested that the antitumor activity of GP11 may be due to the improvement of immune functions through the TLR-4-mediated up-regulation of NO and TNF-α.

The photosynthetic capacity and efficiency of a crop depends on the biosynthesis of photosynthetic pigments and chloroplast development. However, little is known about the molecular mechanisms of chloroplast development and chlorophyll (Chl) biosynthesis in common wheat because of its huge and complex genome. Ygm, a spontaneous yellow-green leaf color mutant of winter wheat, exhibits reduced Chl contents and abnormal chloroplast development. Thus, we searched for candidate genes associated with this phenotype. Comparative transcriptome profiling was performed using leaves from the yellow leaf color type (Y) and normal green color type (G) of the Ygm mutant progeny. We identified 1227 differentially expressed genes (DEGs) in Y compared with G (i.e., 689 upregulated genes and 538 downregulated genes). Gene ontology and pathway enrichment analyses indicated that the DEGs were involved in Chl biosynthesis (i.e., magnesium chelatase subunit H (CHLH) and protochlorophyllide oxidoreductase (POR) genes), carotenoid biosynthesis (i.e., &beta, carotene hydroxylase (BCH) genes), photosynthesis, and carbon fixation in photosynthetic organisms. We also identified heat shock protein (HSP) genes (sHSP, HSP70, HSP90, and DnaJ) and heat shock transcription factor genes that might have vital roles in chloroplast development. Quantitative RT-PCR analysis of the relevant DEGs confirmed the RNA-Seq results. Moreover, measurements of seven intermediate products involved in Chl biosynthesis and five carotenoid compounds involved in carotenoid-xanthophyll biosynthesis confirmed that CHLH and BCH are vital enzymes for the unusual leaf color phenotype in Y type. These results provide insights into leaf color variation in wheat at the transcriptional level.

Fe2O3 and CeO2 modified activated coke (AC) synthesized by the equivalent-volume impregnation were employed to remove elemental mercury (Hg(0)) from simulated flue gas at a low temperature. Effects of the mass ratio of Fe2O3 and CeO2, reaction temperature, and individual flue gas components including O2, NO, SO2, and H2O (g) on Hg(0) removal efficiency of impregnated AC were investigated. The samples were characterized by Brunauer-Emmett-Teller (BET), X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). Results showed that with optimal mass percentage of 3 % Fe2O3 and 3 % CeO2 on Fe3Ce3/AC, the Hg(0) removal efficiency could reach an average of 88.29 % at 110 °C. Besides, it was observed that O2 and NO exhibited a promotional effect on Hg(0) removal, H2O (g) exerted a suppressive effect, and SO2 showed an insignificant inhibition without O2 to some extent. The analysis of XPS indicated that the main species of mercury on used Fe3Ce3/AC was HgO, which implied that adsorption and catalytic oxidation were both included in Hg(0) removal. Furthermore, the lattice oxygen, chemisorbed oxygen, and/or weakly bonded oxygen species made a contribution to Hg(0) oxidation.

Co–Ce mixed oxides were loaded on commercial cylindrical activated coke granules (CoCe/AC) by an impregnation method to remove gaseous elemental mercury (Hg0) from simulated coal combustion flue gas at low temperature (110–230 °C). Effects of the Co/Ce molar ratio in Co–Ce mixed oxides, mixed oxides loading value, reaction temperature, and flue gas components (O2, NO, SO2, H2O) on Hg0 removal efficiency were investigated, respectively. Brunauer–Emmett–Teller analysis, X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis (TGA), and X-ray photoelectron spectroscopy (XPS) analysis were employed to analyze the characteristics of the samples. Results showed that up to 92.5% of Hg0 removal efficiency could be obtained over Co4.5Ce6/AC at 170 °C. The remarkably high Hg0 removal ability of Co4.5Ce6/AC mainly depended on the synergetic effect between cobalt oxide and ceria. Additionally, different with the pure N2 condition, the existence of O2 and NO...

Aims/Introduction The present study was designed to evaluate the effect of chromium malate on glycometabolism, glycometabolism-related enzyme levels and lipid metabolism in type 2 diabetic rats, and dose–response and curative effects. Materials and Methods The model of type 2 diabetes rats was developed, and daily treatment with chromium malate was given for 4 weeks. A rat enzyme-linked immunosorbent assay kit was used to assay glycometabolism, glycometabolism-related enzyme levels and lipid metabolism changes. Results The results showed that the antihyperglycemic activity increased with administration of chromium malate in a dose–dependent manner. The serum insulin level, insulin resistance index and C-peptide level of the chromium malate groups at a dose of 17.5, 20.0 and 20.8 μg chromium/kg bodyweight were significantly lower than that of the model, chromium trichloride and chromium picolinate groups. The hepatic glycogen, glucose-6-phosphate dehydrogenase and glucokinase levels of the chromium malate groups at a dose of 17.5, 20.0 and 20.8 μg chromium/kg bodyweight were significantly higher than that of the model, chromium trichloride and chromium picolinate groups. Chromium malate at a dose of 20.0 and 20.8 μg chromium/kg bodyweight significantly changed the total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglycerides levels compared with the chromium trichloride and chromium picolinate groups. Conclusions The results showed that chromium malate exhibits greater benefits in treating type 2 diabetes, and the curative effect of chromium malate is superior to chromium trichloride and chromium picolinate.

Interference effects between the dominant waves created by the bow and the stern of a monohull ship, of length L , that advances at constant speed V along a straight path in calm water of uniform finite depth D are considered. The largest waves due to constructive interference result in an apparent wake angle ψ max that can differ greatly from the cusp or asymptote angles associated with the wave pattern of a ship when interference effects are ignored, as in Kelvin’s classical analysis. Thus, wave interference has a very large effect on the wave signature of a ship in shallow water and cannot be ignored. Water-depth effects on the wake angle ψ max are found to be insignificant for water depths d L ≡ D / L greater than d deep L ≈ 0.89 or for Froude numbers F ≡ V / g L greater than F deep ≈ 0.5 / d L . Furthermore, the water depth d L has only a relatively small influence on the wake angle ψ max for 1.5 F , and the deep-water approximation ψ max ≈ 0.14 / F 2 can then be used.

A theoretical explanation of observations of high-Froude-number ship wakes that are narrower than the classical Kelvin 3 9 ∘ angle was recently offered by Rabaud and Moisy. The explanation relies on the assumption that a ship hull does not create waves longer than its length. A validation of this theoretical model has also been given. The validation is based on the approximation of the flow created by a ship hull by means of a Gaussian distribution of pressure at the free surface. These two flow models predict a wake angle ψ m a x that decreases like 1 / F as the Froude number F increases beyond F ≈ 0.5 . A third theoretical explanation was recently proposed by the authors. This theoretical explanation assumes that the wave pattern of a ship mostly consists of dominant waves that are created by the ship bow and stern, and is mostly determined by interference effects between these dominant waves. The analysis of interference effects on the Kelvin wake of a ship predicts a wake angle ψ m a x ≈ 0.14 / F 2 for a monohull ship, or ψ m a x ≈ 0.2 b / F for a catamaran with beam/length ratio b . The ‘flow models’ underlying these three alternative theoretical explanations of narrow ship wakes are examined, and the corresponding theoretical predictions are compared to the 37 observations of ship wakes reported by Rabaud and Moisy for Froude numbers F within the wide range 0.1 F 1.7 . The wake observations are found to be consistent with the predictions given by an analysis of interference between the bow and stern waves of a monohull ship, or a catamaran with beam/length ratio b within the range 0.4 ≤ b ≤ 0.8 . Indeed, agreement is consistently strong for the 35 wake observations within the range 0.1 F 1.4 . This range of Froude numbers includes the range F 0.6 , where interference between transverse bow and stern waves is important, and corresponds to the vast majority of ships. The predictions given by the Rabaud–Moisy ‘cutoff-wavelength model’ and the ‘Gaussian pressure distribution model’ are in close agreement with two wake observations for 1.6 F 1.7 and may also be consistent with several wake observations for 0.6 F 1.4 , but are not consistent with most observations. This finding and a critical examination of the assumptions underlying the Rabaud–Moisy model and the Gaussian pressure distribution model suggest that these theoretical models may not be realistic for most ships. This conclusion is further validated by numerical computations of wave patterns for F = 1 . The computed waves are largest along a ray angle that agrees with the prediction of the bow and stern waves interference model, but is noticeably smaller than predicted by the Gaussian pressure distribution model.

The yellow-green leaf color mutant (Ygm) is a spontaneous mutant derived from the common wheat (Triticum aestivum L.) cultivar Xinong1718. Genetic analysis has shown that a novel single incompletely dominant gene (Y1718) is responsible for the yellow leaf color phenotype. The progeny of Ygm exhibit three distinct leaf color phenotypes, i.e., yellow (Y), yellow-green (Yg), and normal green (G). Y plants have yellow-green leaves in the seedling stage, which become yellow or a strong gold-yellow in the booting stage, with dwarfism and thin tillers until the flowering stage, and underdeveloped thylakoid membranes without well-structured grana in the chloroplasts. Yg plants always have a yellow-green phenotype with a number of well-structured grana that are loosely connected with stroma lamellae in the chloroplasts, where their main agronomic traits are the same as Xinong1718 and G plants, but the seed yield is low. Compared with Xinong1718 and G plants, Y and Yg plants had much lower chlorophyll (Chl) a, Chl b, and carotenoid contents in the booting stage. Molecular analysis using an F2 population and F2:3 lines derived from a cross of Yg and Shannong1 indicated that the Y1718 gene is located on chromosome 2BS, where it is flanked by the simple sequence repeat marker Xwmc25 and expressed sequence tag-sequence tagged sites marker BE498358 at genetic distances of 1.7 and 4.0 cM, respectively. Our results facilitate the fine mapping and gene cloning of Y1718 to explore chlorophyll synthesis, metabolism, and development in wheat.

The Neumann-Michell linear potential flow theory of the short farfield waves created by a ship that advances at a constant speed in calm water is coupled with nonlinear analytical relations for inviscid flow along the wave profile at the ship hull surface, i.e., the contact line between the ship hull surface and the free surface. This ad hoc coupling of linear farfield ship waves and a nonlinear nearfield flow along a ship waterline determines short farfield ship waves in terms of the free-surface elevation along the ship hull surface, and provides insight into the influence of nearfield nonlinearities (most significant at a ship waterline) on short farfield ship waves. For the Wigley parabolic ship model, nearfield nonlinearities are found to be relatively weak and to have a limited, although appreciable, influence on short farfield waves. The steepness of divergent ship waves is also analyzed. This analysis shows that, for a full-scale Wigley hull, divergent waves are too steep to exist inside a broad inner Kelvin wake with angle roughly equal to 13°, i.e., a third of Kelvin’s 39° ship wake angle.

Our previous study showed that chromium malate improved the composition of intestinal flora, glycometabolism, glycometabolism-related enzymes, and lipid metabolism in type 2 diabetes mellitus (T2DM) rats. The present study was designed to evaluate the effect of chromium malate with long-term supplementation on short chain fatty acid (SCFA) content in Sprague-Dawley rats. The samples were analyzed by gas chromatography with high linearity (R 2 ≥ 0.9995), low quantification limit (0.011-0.070 mM), and satisfactory recoveries. The method was simple and environmentally friendly. The acetic content in cecum of 3-month control group was significantly higher than that of 1-year control group. When compared with 1-year control group, chromium malate (at a dose of 20.0 μg Cr/kg bw) could significantly increase acetic, propionic, i-butyric butyric, butyric, i-valeric, valeric, and n-caproic levels. The acetic, propionic, i-butyric, valeric, and n-caproic contents of 1-year chromium malate group (at a dose of 20.0 μg Cr/kg bw) had a significant improvement when compared with 1-year chromium picolinate group. Acetic, propionic, and butyric contained approximately 91.65 % of the total SCFAs in 1-year group. The results indicated that the improvement of chromium malate on short chain fatty acid content change was better than that of chromium picolinate.

Fe2O3 and CeO2 modified activated coke (AC) synthesized by the equivalent-volume impregnation were employed to remove elemental mercury (Hg(0)) from simulated flue gas at a low temperature. Effects of the mass ratio of Fe2O3 and CeO2, reaction temperature, and individual flue gas components including O2, NO, SO2, and H2O (g) on Hg(0) removal efficiency of impregnated AC were investigated. The samples were characterized by Brunauer-Emmett-Teller (BET), X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). Results showed that with optimal mass percentage of 3 % Fe2O3 and 3 % CeO2 on Fe3Ce3/AC, the Hg(0) removal efficiency could reach an average of 88.29 % at 110 °C. Besides, it was observed that O2 and NO exhibited a promotional effect on Hg(0) removal, H2O (g) exerted a suppressive effect, and SO2 showed an insignificant inhibition without O2 to some extent. The analysis of XPS indicated that the main species of mercury on used Fe3Ce3/AC was HgO, which implied that adsorption and catalytic oxidation were both included in Hg(0) removal. Furthermore, the lattice oxygen, chemisorbed oxygen, and/or weakly bonded oxygen species made a contribution to Hg(0) oxidation.

Our previous study showed that chromium malate improved the regulation of blood glucose in mice with alloxan-induced diabetes. The present study was designed to evaluate the 90-day oral toxicity of chromium malate in Sprague-Dawley rats. The present study inspected the effect of chromium malate on glycometabolism, glycometabolism-related enzymes, lipid metabolism, and learning and memory ability in metabolically healthy Sprague-Dawley rats. The results showed that all rats survived and pathological, toxic, feces, and urine changes were not observed. Chromium malate did not cause measurable damage on liver, brain, and kidney. The fasting blood glucose, serum insulin, insulin resistance index, C-peptide, hepatic glycogen, glucose-6-phosphate dehydrogenase, glucokinase, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglyceride levels of normal rats in chromium malate groups had no significant change when compared with control group and chromium picolinate group under physiologically relevant conditions. The serum and organ content of Cr in chromium malate groups had no significant change compared with control group. No significant changes were found in morris water maze test and superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and true choline esterase (TChE) activity. The results indicated that supplementation with chromium malate did not cause measurable toxicity and has no obvious effect on glycometabolism and related enzymes, learning and memory ability, and related enzymes and lipid metabolism of female and male rats. The results of this study suggest that chromium malate is safe for human consumption.